1. Field of the Invention:
This invention relates to a strainless precision process on radical (free radical) reaction and, more particularly, to a precision process ensuring strainless cutting, boring and grinding of brittle materials hard to work such as silicon and germanium single crystal for manufacturing semiconductors, gallium-arsenic compound, various ceramics materials or the like.
2. Description of the Prior Art:
A prior art precision process, or cutting for example, of brittle materials hard to work such as silicon and germanium single crystal for manufacturing semiconductors, gallium-arsenic compound, various ceramics materials or the like depends only on dicing on a diamond wheel, and since its working principle comprises a brittle fracture by fine cracking, a serviceable surface will not be secured due to residual cracks unless the cut face is removed about 100 .mu.m in thickness on the average. Further, the brittle fracture due to cracks is rather probable and a considerably large crack may remain according to circumstances, which is capable of deteriorating the reliability of an obtained surface. Thus, the cut face of a workpiece must be removed at about 100 .mu.m in thickness, for which lapping is employed, however, since its working principle also comprises a brittle fracture, a residual affected layer is rather deep while not so heavy as compared with the aforementioned dicing, and thus an after-treatment such as etching, polishing or the like is further required. Then, lapping is also carried out for grinding the surface of a workpiece, however, the lapping is realized by transferring the flatness of a lapping tool to the workpiece, and since it depends in this case on a brittle fracture likewise according to a conventional process using a grade, both surface roughness and surface property are not to withstand the final purpose. Further, the prior art process is that of utilizing a thermal fusion phenomenon on laser for boring, grooving and so forth, therefore a thermal affected layer or a residual crack arsing on thermal stress is present on a finished surface. Thus in the prior art process, not only a residual crack and a thermal affected layer are present on the finished surface, but also a finished portion is removed so much, therefore yield of a workpiece is high, and further a production process increases in number, thus preventing a cut in cost of semiconductors and others using expensive silicon and germanium single crystal, or gallium-arsenic compound.